1. Field of the Invention
The present invention relates to a stitch pattern sewing machine and, more specifically, to a stitch pattern sewing machine capable of sewing original patterns in different sizes.
2. Description of the Related Art
Some conventional stitch pattern sewing machines capable of sewing a plurality of patterns including characters and symbols allow the selection of a desired pattern through the operation of numeric keys and the optional selection of a pattern size for the selected pattern. Generally, each pattern has a predetermined standard size which can be changed within a predetermined range by manually operating a switch or the like. The conventional stitch pattern sewing machine of the type described stores data of a plurality of needle locations to control the needle for pattern sewing. In sewing a selected pattern in a selected pattern size, the distance between the adjacent needle locations is increased or decreased according to the selected pattern size. Some conventional sewing machines store pattern data for a multiple overlap stitch, namely, data for forming multiple stitches between two needle locations.
However, a problem arises in enlarging or reducing the original pattern; that is, since the original pattern is designed with reference to a standard pattern size, the image of an enlarged or reduced stitch pattern differs from that of the corresponding original pattern. This is because the apparent thickness of lines delineating the stitch pattern relative to the pattern size decreases and hence the stitch pattern looks lean when the original pattern is enlarged. On the other hand, the apparent thickness of lines delineating the stitch pattern relative to the pattern size increases and details of the pattern cannot be expressed clearly when the original pattern is reduced. Furthermore, when the original pattern is reduced, stitches are liable to interfere with each other because the distance between the adjacent needle locations is decreased.